Typewriter



R. ATTI ET AL Aug. 20, 1935.

TYPEWRITER Filed Aug. 24, 1931 3 Sheets-Sheet l 5 m? x m i A WM 5 Aug.20, 1935. R. ATTI El AL 2,011,700

TYPEWRITER Filed Aug. 24, 1931 3 Sheets-Sheet 2 WEB, 2.5

l VENTORS PAL PM 2 TT/ CLAUDE 7. 8/6,:

ATTORN EYS Aug. 20, 1935. R. ATI'I El AL 2,011,700

TYPEVIRITER Filed Aug. 24. 1931 3 Sheets-Sheet 3 ENTORS IN RALPH TT/ CLQl/OE fE/CE ATTORNEYS Cit iii

Patented Aug. 20, 1935 UNITED STATES ccliiilil HUG PATENT OFFICETYPEWRITER Application August 24,

17 Claims.

This invention relates to typewriters and more particularly to a shiftmechanism and type action for noiseless typewriters. It is animprovement on the invention disclosed in the application of Ralph Atti,Serial No. 337,757, filed February 6, 1929, now Patent No. 1,864,521,issued June 28, 1932.

It is the principal object of this invention to provide an improvedshift mechanism for noiseless typewriters of the fixed platen top strokeprinting type.

Another object of this invention is to provide a shift mechanism fortypewriters in which the printing bar is projected in rectilinear motioninto position ready to print and in which the projecting means ispivotally mounted on a shiftable pivot operated by the shift key topermit shifting from one case letter to another.

Another object of this invention is to provide an improved noiselesstype action for top stroke printing by a rectilinear movement which hasa higher acceleration and a higher velocity of the printing bar thanheretofore known constructions.

Another object of this invention is to provide an improved system ofstaggering the type heads to provide for a uniform and additionalclearance in a rectilinear moving printing bar.

Another object of this invention is to provide a printing bar withangularly disposed type in the line of movement of a rectilinearlymoving type carrier for multiple case type heads.

Further objects and advantages of this invention will appear from thefollowing description thereof taken in connection with the attacheddrawings which illustrate a preferred form of embodiment of our deviceand in which- Figure 1 is a side elevation of the type actuatingmechanism.

Figs. 2, 3 and 4 diagrammatically illustrate different steps in theprinting action,

Figure 5 is a schematic partial plan view of the typewriter mechanism,

Figs. 6, 7, and 8 are top plan views of the ends of different printingbars,

Figure 9 is a side elevation of adjacent printing bars,

Figure 10 is an end elevation of adiacent type heads, and

Figure 11 is a side elevation of a modified form of type shift.

The actuating mechanism chosen as an illu trative embodiment of theinvention is shown in Figure 1 and comprises a type lever l0 which ispivoted to a fixed pivot l I which will be mount- 1931, Serial No.558,896

type key M. A link I5 is pivoted to the type lever 1 I0 and to theintermediate lever l2, in such manner that the freely moving end IE willhave an arcuate movement about the fixed pivot I3 and such movement dueto the difference in leverage will be extremely rapid on a normaldownward movement of the type lever key M.

A modified form of bell crank I! having a small angle between theoperating arms is mounted on a shiftable pivot I8, one arm of the bellcrank I! being secured to a link l9 which is connected to theintermediate lever l2 at the freely movable end l6, and the other leverarm of the bell crank being secured to the cam lever 20 at the freelymovable end 2|. The cam lever 20 is pivoted to the type carrier 22 atthe point 23, the type carrier 22 being slidable in a rectilineardirection in the type carrier guides 24, which in a complete embodimentof the device will be suitable combs on a plate carried from the frame.A printing bar 25 preferably of balanced construction is pivoted at 22bto the type carrier 22, and on one end of the printing bar is the typehead 26 carrying the respective type 21 and 21a, the type 21 being uppercase letters, and the type 21:; being lower case letters. The oppositeend of the balanced printing bar 25 is provided with a cam follower 28which cooperates with the cam 29, which is integral with the actuatingcam lever 20'. The cam surface on the cam 29 is for a major portion 29a,substantially inactive, giving a period of dwell and is provided with alift portion 29b and a final dwell portion 290 which is also inactive.This structure is only diagrammatically shown in Fig. 1 to illustrate asingle type action. In a complete machine there will be a plurality ofsimilar linkages and carriers mounted in a suitable frame and alloperated from a standard key board and comprising the usual or anypreferred arrangement of type and operating keys.

The operation of the type motion for one case of type is shown in Figs.2 and 3. The type lever key M as first depressed rotates theintermediate lever l2 through the link l5 and causes an instantaneousbreaking of the straight line reis then projected forwardly under highacceleration which directly moves the type carrier 22 to which it isconnected. This downward movement of the free end of the lever l2 thusexerts the greatest possible force to bring about the rapid initialacceleration of the type carrier. The dwell surface 29a on the cam asshown may move under the follower without causing rotational movement ofthe printing bar during this period.

On the further movement of the type lever key I4, the bell crank armattached to the cam lever passes through a right angle position and thelinks l9 and will become perpendicular with respect to the intermediatelever l2 and type lever ID. This position is shown in Fig. 3 and all ofthe energy and motion of the type lever key 4 will be used for the highvelocity movement of the type carrier 22. Such movement comes intoeffect after the initial acceleration. and the position of rest of thebell crank I! in Fig. 1 will not interfere with the high velocitymovement of the type carrier as the right angle relation between thebell crank arm and the cam lever 20 will be reached immediately afterthe straight line relation between the link I9 and intermediate lever I2is broken.

On further movement of the type lever key 4, the position is reachedshown in Figure 3. The straightening of the toggle between the cam lever20 and the arm of the bell crank effectively stops further movement ofthe type carrier, so that the printing bar is in position over theplaten 30. At the same time, the cam 29 has passed through the dwellperiod 29a and the follower 28 is forced upward by the lift portion 29band the printing is accomplished.

A stop 33 prevents the movement of the toggle members 20 and I1 beyondthe straight line position and the stop 38 cooperates with theintermediate lever l2 to prevent its movement beyond the fixed point.

This description of the preceding action is typical of the actionwhether lower case or upper case letters do the printing. The action hasfirst rapid acceleration, then high velocity, finally a simultaneousrapid deceleration to a stop and cam actuated printing, and the printingis thus noiseless and rapid due to the cam actuation.

In order to assist the return of the parts in a rapid manner, and tobalance the action on the typing movement, counter-weights |2a and Haare placed on the intermediate lever l2, and the bell crank I'Irespectively, and a suitable stop 3| is provided for cushioning andlimiting the stroke of the intermediate lever I2, and the cam actuatedlever 20 respectively. A suitable return spring 32 is also used inconnection with the intermediate lever 2, and a spring 22a is used tomaintain the cam follower on the cam 29 and maintain the type head outof printing position.

Shifting of the printing bar from lower case letters to upper caseletters is brought about by the shift key lever 36 which is pivoted at31 and has a link 39 connected to a pair of links 40 and 4|. The link 40is secured to a fixed pivot 42 and the link 4| is secured to the pivotI8 of the bell crank I! which may preferably be carried by the block 34movable in slot or channel 35 to guide the movement of the pivot in adirection parallel to movement of the printing bar 25. On the depressionof the shift key lever 36 and the movement of this lever about its fixedpivot 31, the link 39 draws the two links 40 and 4| into a V shape, thusmoving the bell crank pivot from its lower case position ll into uppercase position I811, as shown in Fig ure 4. This movement of the pivot l8to its new position l8a is equivalent to the distance between the uppercase and lower case type which is approximately A; inch and suchmovement will limit the forward movement of the type carrier to suchextent. This movement will have substantially no effect on the movementof the bell crank or associated parts as to acceleration or velocity asthe angular change brought about is negligible. No movement of theplaten is necessary and the type shift will effectively and quicklychange the type printing and will not interfere with the noiseless typeaction.

The type heads are provided with upper case and lower case letters 21and 21a, as shown in Figs. 6, 7, and 8. The printing bar moving in thecenter of the bank of keys has the upper case and lower case letters 21'and 21a in direct alignment. This construction is particularly shown inFigure 6.

An extreme position is shown in Figure 7 in which due to the rectilinearmotion of the printing bar 25a the type 21 and 21a are not in alignmentwith the printing bar but on the contrary are at an angular relationthereto which angle is equivalent to the angle between the printing barand the central printing bar or a line perpendicular to the platen. Boththe upper case and lower case type are parallel, and parallel lines bearthe same angular relation to the printing bar as the type carrier doesto the central type carrier or a line perpendicular to the platen.

The other extreme position of type carrier is shown in Figure 8 and inthis figure the upper case and lower case letters are also angularlyplaced with respect to the printing bar 25b and this angle is alsoequivalent to the angle between the particular printing bar and a lineperpendicular to the platen. The angle however, is opposite to theprevious angle.

This angular relation is essential due to the rectilinear motion of theprinting bar and the top stroke printing action. Such constructionpermits a direct engagement of the type heads 26 on the printing bars 25and each printing head although separately formed due to the angularrelation and different character of the type may be integrally securedto the printing bar, without any other correction for angle or offset ofthe printing head as the ofiset is taken care of by the angular relationof the type on the type heads 26. A modified form of type shiftconstruction is shown in Figure II in which the type shift lever 36aoperates to laterally move the pivot I3 of the intermediate lever l2 andsimultaneously to move the pivot l8 of the modified bell crank H whichare joined by a connecting bar 45. Both pivots are preferably carried byblocks 34:; and 34, movable in suitable slots or channels 35a and 35respectively. A connecting link 39a connects the type shift lever 36awhich is pivoted at 31a to a pair of toggle members 40a and 4| 0.. Thetoggle member 40a is fixed to the pivot point 42a and the toggle member4 la is secured to the pivot [3 or the block 34a carrying such member.On depression of the type shift lever 36a, the toggles will move into aV-shape substantially as shown in Figure 4, but will move both the pivotl3 and the pivot l8 and the connecting member 45 in radial directioninstead of only moving pivot l8 as in first form. Such movement willcause the link I!) to break from the straight line position and willcause a partial movement of the type llll-liluluvu lllll 4l1 carrierthrough the movement of the bell crank arm which will be equivalent tothe distance between the type and thus the type carrier will be movedfrom the lower case to the upper case position. The movement of thepivot l3 and of pivot l8 or the movement of the pivot 18 singly is in astraight line direction parallel to the movement of the type carrier.

In order that all of the type carriers may be placed in the requiredsmall segment as shown in Figure 5 without the necessity of multiplyingthe number of type on each printing bar, the type heads 26 may bestaggered as shown in Figs. 9 and 10. The type head 26 on one printingbar 25 has a position slightly higher than that of the adjacent typehead in such a manner that the type carriers do not contact with eachother until the type is moved to a position substantially intermediatebetween the printing position and the rest position. The construction ofthe printing bar for such an arrangement is additionally shown in Figure9, it being noted that one printing bar 25 can be in a raised positionso that it will normally clear the paper and the platen, whereas theadjacent printing bar 250 is raised a further amount which amount isslightly greater than the tickness of the type head 26.

Such construction requires a slightly diiferent cam surface on the cam29 and the adjacent cam 29d will have a lower dwell portion and willhave a lift substantially double that of the first cam to bring the typehead into the same printing position. In operation, the type key will bedepressed in the usual manner and no wedging effect or overlapping ofthe adjacent printing bars will take place and the type carriers may beextended to the intermediate position as shown in Figure 5 before theywill contact with each other. The additional lift necessary is notnoticeable in the typing action as it is brought about by the formationof the toggle by cam lever 20 and bell crank I1.

The operation of this typewriter mechanism thus shows a highacceleration movement in the preliminary step and as the type carrierreaches its position over the platen for printing a straight line isformed by the toggle thus stopping further movement of the type carrier.In such position. the printing is brought about by the straightening ofthis toggle.

The staggering of the type permits a unilateral movement of the typecarriers without doubling up of the type heads on each carrier and thetype carriers can move the usual distance half way to printing positionwithout wedging or overlapping. Shifting from one case type to anotheris brought about by shifting the pivot of the type carrier movingmechanism which controls the distance of the movement of type carrier.Return of the parts is brought about by return springs which are used tobalance the movement, all of which cooperate to return the partsnoiselessly and rapidly. The action of the mechanism will thus effect arapid, noiseless and effortless typing with the minimum number of parts.

While we have shown a preferred form of embodiment of the device, we areaware that other modifications may be made therein and consider that thedescribed apparatus is merely illustrative of our invention and desirethat the description and hereinafter appended claims should receive abroad interpretation within the scope and spirit thereof.

We claim:

1. In a typewriter of the top platen printing type, a type bar, apivoted lever for moving the type bar forward to a position less thanprinting letter to another on said type bar, comprising a pivot blockfor said pivoted lever and a shift lever to shift said pivot block tovary the printing.

2. In a device of the character described, a platen, a key, a type barcarrying a plurality of type, means to guide the movement of said typebar and a single train of connections intermediate said key and saidtype bar whereby said type is first advanced to a point opposite saidplaten and subsequently moved in a direction separate from its firstmovement to effect printing on said platen, said train of connectionsincluding a link to noiselessly stop the movement of the type bar, andtoggle means to shift the movement of the type bar from one type toanother with respect to the platen.

3. In a device of the character described, means mounted for rectilinearmovement, type carrying means pivoted to said first named means, and asingle acting toggle-link adapted to first rapidly move said first namedmeans while said type carrying means is held from rotation about itspivot, and cam means to subsequently rotate said type carrying meansabout its pivot, and means to shift said toggle link for change of typecase.

4. In a device of the character described, a frame, a bar mounted forrectilinear movement upon said frame, a type carrier mounted on said barand actuating means for moving said bar and moving said type carrierrelative to said bar, said actuating means comprising a toggle joint,one of said toggle members being provided with a type depressing cam,the other of said toggle members being a modified bell crank, a pivotfor said bell crank, a second toggle joint, one of said toggle membersbeing connected to the pivot and a type shift lever connected to saidsecond toggle to break said toggle and move said pivot for changing fromone case to another.

5. In a device of the character described, a shift key, a toggle lever,one of said toggle members having a fixed point, a type carrier,actuating means to move said type carrier, one end of said actuatingmeans being secured to the other toggle member, and connecting meansbetween said shift key and said toggle whereby said actuating means ismoved a distance corresponding to the ultimate distance between type tonoiselessly shift from one case type to another.

6. In a device of the class described, a platen, a plurality of pivotedprinting bars, pivots for said printing bars, all of said pivots beingequidistant from the printing point, type heads carried by said bars,type on said type heads, means to effect printing on said platen, meansto position adjacent type heads in staggered relation at a distanceapart substantially equivalent to the thickness of a type head.

7 In a rectilinearly moving top stroke printing mechanism, a pluralityof equal length, pivoted printing bars, a plurality of pivots therefor,each of said pivots being equi-distant from the printing point, typeheads mounted thereon and means to prevent wedging of adjacent typeheads on movement of adjacent printing bars, said means including astaggered arrangement of type heads.

8. In a device of the class described, having a frame, and a platen,printing bars pivoted to slidable supports, toggle levers connected withsaid supports, said toggle levers being shiftably pivoted to said frame,cams on said toggle levers, and cam followers on said printing barscooperating with saidcams, said toggle levers adapted to move saidsupports in substantially rectilinear movement to printing position anda rotary movement to effect printing, said printing bars having typeheads on one end thereof, adjacent type heads being verticallystaggered, and type on said type heads, all of said type being mountedin parallel planes, said printing bars being angularly disposed to saidplanes in amount equivalent to the angle said printing bars make withthe platen axis.

9. In a type action substantially as described a type bar having aplurality of case letters thereon for printing on the top of the platen,pivoted means to move the type bar forward nearly to printing position,additional means to depress the type bar to cause printing therefrom,and means to shift from one case letter to another, comprising a meansto move the pivot of said pivoted means laterally with respect to theplaten to control the ultimate position of the type bar.

10. In a type action for noiseless typewriters including a type bar,means to actuate said type bar and means to stop the type bar beforecontact, a fixed pivot for said latter means, means for shifting fromone case letter to another case which comprises means for shifting theposition of the pivot for said stopping means in a direction parallel tothe movement of the type bar, and cam means, effective after theprojection of said type bar to force said type bar into printingcontact.

11. A type bar action for noiseless typewriters comprising a type barcarrying a printing type, a reciprocable carrier on which said type baris mounted movable to carry the type bar to a projected position, a key,a bell crank, a plurality of links connected to said key and said bellcrank and a link between said bell crank and said type carrier, wherebyon first movement of said key a toggle is broken for primary highacceleration of said reciprocating carrier, and on a second movement ofsaid key said links fall into a right angled relation to move saidcarrier under high velocity, and on a further movement of said key atoggle is made with the bell crank and type carrier connecting link tostop said type carrier, and a cam actuated by a final movement of saidkey to give a printing movement to said type bar in projected position.

12. A type bar action for noiseless typewriters comprising a type barcarrying a plurality of printing characters, a reciprocable carrier onwhich said type bar is mounted movable to carry the type bar to aprojected position, a key, a shiftable pivot, links connected to saidkey, said shiftable pivot and said reciprocable carrier to move saidcarrier and type bar to a projected position upon actuation of the key,a cam actuated by said links to give a printing movement to said typebar when in said projected position, and

means for shifting the shiftable pivot to shift the type bar from oneprojected position to anotherfor changing type case.

13. In a noiseless typewriter of the class described having a type barand means to move the type bar forward adjacent to but out of contactwith the platen, means to depress the type bar to cause printing, andmeans to shift from one case letter to another on said type bar,comprising a normally fixed pivot controlling the ultimate position ofthe type bar, and means to shift the fixed position of said pivot, saidpivot being positively linked to said type bar whereby the point ofprinting is shifted from one case letter to another on said type bar.

14. In a typewriter of the character described, a type bar carrying aplurality of case type, means to move said type bar into a projectedposition, including a bell crank, one arm of which acts as part of atoggle, means to cause printing and means to move the bell crank pivotabout which the bell crank rotates to affect the projected position ofthe type bar in the printing position to change from one case type toanother.

15. A rectilinear type action for top stroke printing which comprises atype carrier, a printing bar carried thereby, a type key lever and aplurality of intermediate toggles, and intermediate linkage to initiallybreak one of said toggles to accelerate said type carrier into aprojected position and to make another toggle to decelerate and stopsaid type carrier in said projected position before the printing barreaches printing position and means to move the printing bar withrespect to the type carrier for final printing.

16. A type action for noiseless typewriters which comprises a printingbar, a type carrier carrying said printing bar, a type key lever and apluralityof intermediate toggles, and intermediate linkage to initiallybreak one of said toggles to accelerate said type carrier into projectedposition and to make another toggle t0 decelerate and stop said typecarrier in said projected position, type shift means controlling thefixed position of the second toggle for changing the projected positionof the type carrier, means on a part of said second toggle cooperatingwith said printing bar to rotate said printing bar on said type carrierfor printing after said type carrier is stopped.

17. In a noiseless printing device, a printing bar, a type bar carrierpivotally supporting said printing bar, means for giving said printingbar a rectilinear movement including two pivoted modified bell cranksand a pivoted actuating lever, one of said bell cranks being secured tothe type carrier, a connecting member secured to the pivot of the otherbell crank, any type shift means to move said connecting member to varythe printing position of said printing bar from one case type toanother.

RALPH A'I'II. CLAUDE T. RICE.

